NEW YORK – Among the wilder notions floating around post-Sept. 11 New York is the high-rise evacuation device called Escape Rescue System.

Developed by a former Israeli general, it is half elevator, half escape pod – a strange, sophisticated device that allows a group of residents or workers trapped inside a building to be lowered down to safety in fire-resistant capsules that move, like a descending train, on a structure's outer shell.

Imagine a multicabined elevator made of fabric and stored, folded like an accordion, atop a building's roof. When an alarm is sounded, the fabric is dropped down the building's side, where it gradually uncoils. There are now five capsules, strung out in a train and connected by 2-inch metal cables to a motor on the roof. As the capsules descend, escaping tenants climb out from their windows and into the machine and are lowered to the street.

“We got together with 30 mechanical engineers and came up with the concept,” said Yoni Shimshoni, a former brigadier general in the Israeli Defense Forces, who created the machine. “No one has ever cracked the puzzle of helping people to escape like that before.”

For more than a year, Shimshoni has been working out the kinks in his device in Tel Aviv, but now he wants to put it to the test. The only real challenge for the system, he said, is a New York City skyscraper.

To that end, he said, he approached the city and tried to get permission for a test. He won the backing of several politicians, most notably City Council Members Yvette D. Clarke, Gale A. Brewer and Peter F. Vallone Jr., all of whom wrote letters of support.

Shimshoni also won the backing of a Midtown landlord, Vornado Realty Trust, which offered to pay the pilot program's million-dollar cost.

Among the arguments Shimshoni put forth was that his machine can travel up, then down, a 40-story high-rise in about eight minutes. One of his machines can hold as many as 150 people, and if two are installed, as he recommends, 300 people can be lowered to safety in less than 10 minutes.

But the city told him no.

In a letter to Shimshoni dated Feb. 6, Joseph F. Bruno, the commissioner of the city's Office of Emergency Management, said that while Escape Rescue System “does seem, in theory, to present an alternate means of egress,” there were nonetheless concerns. First among them, Bruno wrote, was who would operate it, the Fire Department or civilians at the site?

“While it is envisioned that the control of the system would be under the Fire Department, it is likely that in an emergency building management would put the escape system into operation at their discretion,” Bruno wrote.

He also said he was troubled by a system that would have to “pass by floors where an active fire is taking place.” Finally, he noted what might be called the Titanic effect: In mobile pods with a capacity of only 30 people each, who, in an emergency, would get the first chance to escape?

Such questions hardly trouble Shimshoni. To him, they are proof that his system should be tested in New York. “The way you deal with questions,” he said, “especially with something that's so innovative, is through a pilot test.”

Shimshoni said he has not given up on trying to convince officials in the city. “We plan to continue the process in New York,” he said. “We don't expect this to be the final word.”